Scan sense driver and display device including the same

ABSTRACT

A scan sense driver includes a scan driver and a sense driver. The scan line driver provides a scan line enable signal based on a plurality of clock signals, a global clock signal, and a scan input signal during a scan time interval. The sense driver provides a sense enable signal based on the clock signals and a sense input signal during a sense time interval. The sense driver provides the sense enable signal during a period when an organic light-emitting diode of a pixel is to be tested for a malfunction.

CROSS REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2014-0147490, filed on Oct. 28, 2014,and entitled “Scan Sense Driver and Display Device Including the Same,”is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

One or more embodiments described herein relate to a scan sense driverand display device including a scan sense driver.

2. Description of the Related Art

As the radiation time of an organic light-emitting diode increases,luminous efficiency may decrease. When the luminous efficiency of anorganic light-emitting diode decreases, the image generated by a displaydevice which includes the organic light-emitting diode may degrade.

SUMMARY

In accordance with one or more embodiments, a scan sense driver includesa scan line driver to provide a scan line enable signal based on aplurality of clock signals, a global clock signal, and a scan inputsignal during a scan time interval; and a sense driver to provide asense enable signal based on the clock signals and a sense input signalduring a sense time interval, wherein the sense driver is to provide thesense enable signal during a period when an organic light-emitting diodeis to be tested for a malfunction.

Waveforms of the clock signals provided during the scan time intervalmay be different from the waveforms of the clock signals provided duringthe sense time interval. A time interval when the clock signals providedduring the scan time interval have a first logic level may be a firsttime interval, a time interval when clock signals provided during thesense time interval have the first logic level may be a second timeinterval, and the second time interval is different from the first timeinterval. The sense input signal may have a second logic level duringthe scan time interval. The scan input signal may have a second logiclevel during the sense time interval.

A time interval between adjacent ones of the clock signals providedduring the scan time interval may be a third time interval, and a timeinterval between adjacent ones of the clock signals provided during thesense time interval may be the second time interval. The first timeinterval may be greater than the third time interval. The first timeinterval may be longer than a horizontal time having a predeterminedtime interval, and the third time interval may be substantially equal tothe horizontal time. The second time interval may be greater than thefirst time interval. The first time interval may be substantially equalto the third time interval. The first time interval and the third timeinterval may correspond to a horizontal time, and the horizontal timemay have a predetermined time interval.

The sense driver may provide the sense enable signal based on a totaloperation time, and the total operation time may include a time when thescan sense driver is to operate. The sense driver may provide the senseenable signal when scan sense driver is turned-on.

In accordance with one or more embodiments, a display device includes acontroller to provide a plurality of clock signals, a global clocksignal, a scan start pulse, and a sense start pulse; a plurality of scansense drivers to provide scan line enable signals and sense enablesignals based on the clock signals, the global clock signal, the scanstart pulse, and the sense start pulse; and a pixel array to operatebased on the scan line enable signals and the sense enable signals,wherein each of the scan sense drivers includes: a scan line driver toprovide the scan line enable signal based on the clock signals, theglobal clock signal, and a scan input signal during a scan timeinterval; and a sense driver to provide the sense enable signal based onthe clock signals and a sense input signal during a sense time interval,wherein the sense driver is to provide the sense enable signal during aperiod when an organic light-emitting diode of a pixel in the pixelarray is to be tested for a malfunction.

The scan input signal input into a first scan sense driver of theplurality of scan sense drivers may be the scan start pulse, and thesense input signal input into the first scan sense driver of theplurality of scan sense drivers may be the sense start pulse. The pixelmay include a scan driver to provide a voltage corresponding to datavoltage to a organic light-emitting diode; and a sensor to test for amalfunction of the organic light-emitting diode based on the senseenable signal.

The controller may control waveforms of the clock signals based on thescan time interval and the sense time interval. The controller mayprovide the clock signals, a time interval when the clock signalsprovided during the scan time interval may have a first logic level is afirst time interval, a time interval when the clock signals providedduring the sense time interval have the first logic level may be asecond time interval, and the second time interval may be different fromthe first time interval.

A time interval between adjacent ones of the clock signals providedduring the scan time interval may be a third time interval, a timeinterval between adjacent ones of the clock signals provided during thesense time interval may be the second time interval, the first timeinterval is greater than the third time interval, and the second timeinterval is greater than the first time interval. The first timeinterval may be equal to the third time interval, the first timeinterval and the third time interval may correspond to a horizontaltime, and the horizontal time may be a predetermined time interval.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIG. 1 illustrates an embodiment of a scan sense driver;

FIG. 2 illustrates an embodiment of a scan line driver;

FIG. 3 illustrates an example of control signals for the scan linedriver;

FIG. 4 illustrates an embodiment of a sense driver;

FIG. 5 illustrates an example of control signals for the sense driver;

FIG. 6 illustrates an example of clock signals in scan and sense timeintervals;

FIG. 7 illustrates another example of control signals for the scan linedriver;

FIG. 8 illustrates another example of clock signals in scan and sensetime intervals;

FIG. 9 illustrates an example of the operation of sense driver of FIG.1;

FIGS. 10 to 12 illustrate examples describing a scan input signal and asense input signal in a scan time interval and a sense time interval;

FIG. 13 illustrates an embodiment of a display device;

FIG. 14 illustrates an embodiment of a pixel of the display device;

FIG. 15 illustrates an example of control signals for the displaydevice;

FIG. 16 illustrates an example of control signals for the display deviceduring a sense time interval; and

FIG. 17 illustrates an embodiment of a mobile device.

DETAILED DESCRIPTION

Example embodiments are described more fully hereinafter with referenceto the accompanying drawings; however, they may be embodied in differentforms and should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully conveyexemplary implementations to those skilled in the art. In the drawings,the dimensions of layers and regions may be exaggerated for clarity ofillustration. Like reference numerals refer to like elements throughout.

FIG. 1 illustrates an embodiment of a scan sense driver 10 whichincludes a scan line driver 100 and a sense driver 300. The scan linedriver 100 provides a scan line enable signal SCAN_EN based on aplurality of clock signals CLK1 to CLK3, a global clock signal GCLK, anda scan input signal SCAN_EN during a scan time interval SCTI. When thescan line enable signal SCAN_EN is enabled, a scan line corresponding tothe scan line enable signal SCAN_EN is enabled.

The sense driver 300 provides a sense enable signal SENSE_EN based onthe clock signals CLK1 to CLK3 and a sense input signal SENSE_IN duringa sense time interval SETI. When the sense enable signal SENSE_EN isenabled, a sense enable transistor (e.g., 617 in FIG. 14) correspondingto the sense enable signal SENSE_EN may be turned-on. When the senseenable transistor is turned-on, a sensing voltage VS, transferred from adata voltage line VDATA_L, is transferred to the organic light-emittingdiode (e.g., 615 in FIG. 14) through the sense enable transistor. Whenthe sensing voltage VS is transferred to the organic light-emittingdiode through the sense enable transistor, a corresponding sensingcurrent IS is transferred to the data voltage line (e.g., VDATA_L inFIG. 14) through the sense enable transistor.

A malfunction, or other abnormal state, of the organic light-emittingdiode may be tested based on the sensing current IS. The scan timeinterval SCTI may be a time interval to enable the scan line. The sensetime interval SETI may be a time interval to test malfunction of theorganic light-emitting diode, which, for example, may be included in apixel array (e.g., 600 in FIG. 13) of a display device. (The circuits inFIGS. 13 and 14 are merely illustrative of one non-limiting embodiment.Different circuits may be used for purposes of testing malfunction of anorganic light-emitting diode in another embodiment).

The scan line driver 100 provides the scan line enable signal SCAN_ENbased on the clock signals CLK1 to CLK3, the global clock signal GCLK,and the scan input signal SCAN_IN during the scan time interval SCTI.The sense driver 300 provides the sense enable signal SENSE_EN based onthe clock signals CLK1 to CLK3 and the sense input signal SENSE_INduring the sense time interval SETI. For example, the clock signals CLK1to CLK3 input into the scan line driver 100 may be equal to the clocksignals CLK1 to CLK3 input into the sense driver 300. Therefore, whenthe scan sense driver 10 is used, the sense enable signal SENSE_EN maybe generated by applying the clock signals CLK1 to CLK3 to the sensedriver 300. In one embodiment, separate pins for the clock signals CLK1to CLK3 input into the sense driver 300 are not used. In this case, thelayout area may be decreased.

FIG. 2 illustrates an embodiment of a scan line driver 100, which, forexample, may correspond to the scan line driver 10 in FIG. 1. FIG. 3 isa timing diagram for describing an example of the operation the scanline driver 100 of FIG. 2.

Referring to FIGS. 2 and 3, the scan line driver 100 includes aplurality of scan transistors 111 to 119. The scan line driver 100provides the scan line enable signal SCAN_EN based on the clock signalsCLK1 to CLK3, the global clock signal GCLK, and the scan input signalSCAN_IN during the scan time interval SCTI. As will be described withreference to FIG. 13, the clock signals CLK1 to CLK3, the global clocksignal GCLK, and the scan input signal SCAN_IN may be provided, forexample, from a controller (e.g., 200 in FIG. 13).

The clock signals CLK1 to CLK3 may be selected from among a plurality ofS-clock signals, e.g., first to fourth S-clock signals SCLK1 to SCLK4.For example, the first clock signal CLK1 may be the fourth S-clocksignal SCLK4. The second clock signal CLK2 may be the first S-clocksignal SCLK1. The third clock signal CLK3 may be the second S-clocksignal SCLK2. The scan input signal SCAN_IN may be a scan start pulseSSP.

The clock signals may have different logic levels. For example, when thefirst clock signal CLK1 is at a logic low level, the first scantransistor 113 connected to the third node N3 may be turned-on. When thefirst scan transistor 113 is turned-on, the fourth node N4 may be at alogic low level. When the fourth node N4 is at a logic low level, thesecond scan transistor 115 may be turned-on. When the second scantransistor 115 is turned-on, the scan line enable signal SCAN_EN may beat a logic high level.

Subsequently, the scan input signal SCAN_IN that is the scan start pulseSSP may be at a logic low level and the second clock signal CLK2 may beat a logic low level. When the second clock signal CLK2 is at a logiclow level, the third scan transistor 119 may be turned-on. When thethird scan transistor 119 is turned-on, the scan input signal SCAN_IN ata logic low level may be transferred to the first node N1. When thefirst node N1 is at a logic low level, the fourth scan transistor 116may be turned-on. When the fourth scan transistor 116 is turned-on, thescan line enable signal SCAN_EN may be the third clock signal CLK3. Inthis case, the scan line enable signal SCAN_EN may at a logic low level.

FIG. 4 illustrates an embodiment of a sense driver, which, for example,may be the sense driver 300 in FIG. 1. FIG. 5 is a timing diagramdescribing an example of the operation of the sense driver 300 of FIG.4.

Referring to FIGS. 4 and 5, the sense driver 300 includes a plurality ofsense transistors 311 to 317 and 319. The sense driver 300 provides thesense enable signal SENSE_EN based on the clock signals CLK1 to CLK3 andthe sense input signal SENSE_IN during the sense time interval SETI. Theclock signals CLK1 to CLK3 and the sense input signal SENSE_IN may beprovided, for example, from a controller (e.g., 200 in FIG. 13).

The clock signals CLK1 to CLK3 may be selected from among a plurality ofS-clock signals, e.g., first to fourth S-clock signals SCLK1 to SCLK4.For example, the first clock signal CLK1 may be the fourth S-clocksignal SCLK4. The second clock signal CLK2 may be the first S-clocksignal SCLK1. The third clock signal CLK3 may be the second S-clocksignal SCLK2. The sense input signal SENSE_IN may be a sense start pulseSESP.

The clock signals may have different logic levels. For example, when thefirst clock signal CLK1 is at a logic low level, the first sensetransistor 313 connected to the eighth node N8 may be turned-on. Whenthe first sense transistor 313 is turned-on, the ninth node N9 may be ata logic low level. When the ninth node N9 is at a logic low level, thesecond sense transistor 315 may be turned-on. When the second sensetransistor 315 is turned-on, sense enable signal SENSE_EN may be at alogic high level.

Subsequently, the sense input signal SENSE_IN that is, the sense startpulse SESP, may be at a logic low level and the second clock signal CLK2may be at a logic low level. When the second clock signal CLK2 is at alogic low level, the third sense transistor 319 may be turned-on. Whenthe third sense transistor 319 is turned-on, the sense input signalSENSE_IN at a logic low level, may be transferred to the sixth node N6.When the sixth node N6 is at a logic low level, the fourth sensetransistor 316 may be turned-on. When the fourth sense transistor 316 isturned-on, the sense enable signal SENSE_EN may be the third clocksignal CLK3. In this case, the sense enable signal SENSE_EN may be at alogic low level.

FIG. 6 illustrates an example of clock signals in the scan time intervaland the sense time interval SETI. Referring to FIGS. 3, 5 and 6,waveforms of the clock signals CLK1 to CLK3 provided during the scantime interval SCTI may be different from the waveforms of the clocksignals CLK1 to CLK3 provided during the sense time interval SETI. In anexample embodiment, a time interval during which the clock signals CLK1to CLK3 provided during the scan time interval SCTI maintain a firstlogic level may be a first time interval. A time interval during whichthe clock signals CLK1 to CLK3 provided during the sense time intervalSETI maintain a first logic level may be a second time interval ST. Thesecond time interval ST may be different from the first time interval.For example, the first logic level may at a logic low level, and thesecond logic level may be at a logic high level. The first time intervalmay be longer (e.g., two times longer) than a horizontal time 1H. Thehorizontal time 1H may be a predetermined time interval. The horizontaltime 1H may be a time interval when, for example, the scan line isenabled.

The sense time interval SETI may be a time interval to test whether anorganic light-emitting diode (e.g., 615 in FIG. 14) is malfunctioning orotherwise in an abnormal state. The time interval when the clock signalsCLK1 to CLK3 provided during the scan time interval SCTI maintain thefirst logic level may be a time interval when the scan line is enabled.The time interval when the clock signals CLK1 to CLK3 provided duringthe sense time interval SETI maintain the first logic level may be atime interval when the sense enable transistor (e.g., 617 in FIG. 14) isenabled to test the malfunction of the organic light-emitting diode.

In one embodiment, the sense time interval SETI may be greater than thescan time interval SCTI. In addition, the time interval when the clocksignals CLK1 to CLK3 provided during the sense time interval SETImaintain the first logic level may be greater than the time intervalwhen the clock signals CLK1 to CLK3 provided during the scan timeinterval SCTI maintain the first logic level. The second time intervalST may be greater than, for example, several microseconds.

In an example embodiment, the time interval between adjacent clocksignals CLK1 to CLK3 provided during the scan time interval SCTI may bea third time interval. For example, during the scan time interval SCTI,the time interval between the time when the first S-clock signal SCLK1transitions from a logic high level to a logic low level and a time whenthe second S-clock signal SCLK2 transitions from a logic high level to alogic low level, may be the third time interval. The third time intervalmay be the horizontal time 1H having a period that is predetermined.

In an example embodiment, the time interval between adjacent clocksignals of the clock signals CLK1 to CLK3 provided during the sense timeinterval SETI may be the second time interval ST. For example, duringthe sense time interval SETI, the time interval between the time whenthe first S-clock signal SCLK1 transitions from a logic high level to alogic low level and the time when the second S-clock signal SCLK2transitions from a logic high level to a logic low level may be thesecond time interval ST. The second time interval ST may be greaterthan, for example, several microseconds.

In an example embodiment, the first time interval may be greater thanthe third time interval. For example, the first time interval may belonger (e.g., two times longer) than a horizontal time 1H. The thirdtime interval may be equal to the horizontal time 1H. In this case, thefirst time interval may be greater than the third time interval.

In an example embodiment, the second time interval ST may be greaterthan the first time interval. For example, the first time interval maybe a time interval when the clock signals CLK1 to CLK3 provided duringthe scan time interval SCTI maintain the first logic level. The secondtime interval ST may be a time interval when the clock signals CLK1 toCLK3 provided during the sense time interval SETI maintain the firstlogic level. The scan time interval SCTI may be a time interval toenable the scan line. The sense time interval SETI may be a timeinterval to test whether the organic light-emitting diode 615 ismalfunctioning or otherwise in an abnormal state. The first timeinterval may be, for example, less than several microseconds, and thesecond time interval ST may be, for example, greater than severalmicroseconds.

FIG. 7 is a timing diagram describing another example of the operationof the scan line driver 100 in FIG. 2. FIG. 8 illustrates anotherexample of clock signals in a scan time interval and a sense timeinterval.

Referring to FIGS. 7 and 8, the first time interval may be equal to thethird time interval. The first time interval may be a time interval whenthe clock signals CLK1 to CLK3 provided during the scan time intervalSCTI maintain the first logic level. The time interval when the clocksignals CLK1 to CLK3 maintain the first logic level may be a timeinterval when the scan line is enabled. The third time interval may be atime interval between adjacent ones of the clock signals CLK1 to CLK3.For example, during the scan time interval SCTI, the time intervalbetween the time when the First S-clock signal SCLK1 transitions from alogic high level to a logic low level and the time when the secondS-clock signal SCLK2 transitions from a logic high level to a logic lowlevel may be the third time interval.

For example, the first logic level may be a logic low level and thesecond logic level may be a logic high level. For example, the firsttime interval and the third time interval may be a horizontal time 1H.The horizontal time 1H may be a predetermined time interval. In thiscase, a time interval when the clock signals CLK1 to CLK3 providedduring the sense time interval SETI maintain the first logic level maybe a second time interval ST.

FIG. 9 illustrates a diagram for describing operation of the sensedriver 300 of FIG. 1 according to one embodiment. Referring to FIGS. 4,5, and 9, the sense driver 300 may include the sense transistors 311 to317 and 319. The sense driver 300 provides the sense enable signalSENSE_EN based on the clock signals CLK1 to CLK3 and the sense inputsignal SENSE_IN during the sense time interval SETI. The clock signalsCLK1 to CLK3 and the sense input signal SENSE_IN may be provided from acontroller (e.g., 200 in FIG. 13). The clock signals CLK1 to CLK3 may beselected among a plurality of S-clock signals, e.g., first to fourthS-clock signals SCLK1 to SCLK4.

In an example embodiment, the sense driver 300 may provide the senseenable signal SENSE_EN based on a total operation time. The totaloperation time may be, for example, a time when the scan sense driver 10operates. In one embodiment, if the total operation time of scan linedriver 100 reaches a predetermined time PDT, the sense driver 300 mayprovide the sense enable signal SENSE_EN to test the malfunction of theorganic light-emitting diode (e.g., 615 in FIG. 14).

In an example embodiment, when the scan sense driver 10 is turned-on,the sense driver 300 provides the sense enable signal SENSE_EN. Forexample, whenever the scan sense driver 10 is turned-on, the sensedriver 300 provides the sense enable signal SENSE_EN to test themalfunction of the organic light-emitting diode. In one embodiment, whenthe sense enable signal SENSE_EN is enabled, the sense enable transistor(e.g., 617 in FIG. 14) corresponding to the sense enable signal SENSE_ENmay be turned-on. When the sense enable transistor is turned-on, thesensing voltage VS transferred from the data voltage line VDATA_L may betransferred to the organic light-emitting diode (e.g., 615 in FIG. 14)through the sense enable transistor. When the sensing voltage VS istransferred to the organic light-emitting diode through the sense enabletransistor, a corresponding sensing current IS may be transferred to thedata voltage line VDATA_L through the sense enable transistor.Malfunction of the organic light-emitting diode 615 may be tested basedon the sensing current IS.

FIGS. 10 to 12 illustrate examples of a scan input signal and a senseinput signal in a scan time interval and a sense time interval.Referring to FIGS. 10 to 12, during the scan time interval SCTI when thescan line is enabled, a display device including the scan sense driver10 may not perform a sensing operation to test the malfunction of theorganic light-emitting diode (e.g., 615 in FIG. 14). In addition, duringthe sense time interval SETI when malfunction of the organiclight-emitting diode 615 is tested, the display device may not performthe operation of transferring the data voltage VDATA by enabling thescan line.

For example, the sense input signal SENSE_IN may be a second logic levelduring the scan time interval SCTI. The first logic level may be a logiclow level and the second logic level may be a logic high level. When thesense input signal SENSE_IN is the second logic level during the scantime interval SCTI, the sensing operation may be stopped. The senseinput signal SENSE_IN may be the sense start pulse SESP. For example,the scan input signal SCAN_IN may be a second logic level during thesense time interval SETI. When the scan input signal SCAN_IN is thesecond logic level during the sense time interval SETI, the operation oftransferring the data voltage VDATA by enabling the scan line may bestopped. The scan input signal SCAN_IN may be the scan start pulse SSP.

FIG. 13 illustrates an embodiment of a display device 20 and FIG. 14illustrates an embodiment of a pixel 610 which may be included in thedisplay device 20.

Referring to FIGS. 13 and 14, the display device 20 includes acontroller 200, at least one scan sense driver unit 400, and a pixelarray 600. The controller 200 outputs a plurality of clock signals CLK1to CLK3, a global clock signal GCLK, a scan start pulse SSP, and a sensestart pulse SESP. The scan sense driver unit 400 includes a plurality ofscan sense drivers. In FIG. 13, the scan sense driver unit isillustratively shown in to include four scan sense drivers 10, 11, 12,and 13. In another embodiment, the scan sense driver unit 400 mayinclude another number of scan sense drivers. Each of the scan sensedrivers 10, 11, 12, and 13 may have a structure, for example, as in FIG.1.

The scan sense driver unit 400 provides scan line enable signalsSCAN_EN[1] to SCAN_EN[3] and sense enable signals SENSE_EN[1] toSENSE_EN[3] based on the clock signals CLK1 to CLK3, the global clocksignal GCLK, the scan start pulse SSP, and the sense start pulse SESP.The pixel array 600 operates based on the scan line enable signalsSCAN_EN[1] to SCAN_EN[3] and the sense enable signals SENSE_EN[1] toSENSE_EN[3].

Each of the scan sense drivers in the scan sense driver unit 400 mayinclude a scan line driver 100 and a sense driver 300, for example, asillustrated in FIG. 1. The scan line driver 100 provides the scan lineenable signal SCAN_EN based on the clock signals CLK1 to CLK3, theglobal clock signal GCLK, and a scan input signal SCAN_IN during a scantime interval SCTI. The sense driver 300 provides the sense enablesignal SENSE_EN based on the clock signals CLK1 to CLK3 and a senseinput signal SENSE_IN during a sense time interval SETI.

For example, the sense driver 300 may provide the sense enable signalSENSE_EN. When the scan line enable signal SCAN_EN is enabled, the scanline corresponding to the scan line enable signal SCAN_EN is enabled.The scan time interval SCTI may be a time interval to enable the scanline. The sense time interval SETI may be a time interval to test formalfunction of the organic light-emitting diode 615 in the pixel array600.

In an example embodiment, the scan input signal SCAN_IN input into thefirst scan sense driver 10 may be the scan start pulse SSP. The senseinput signal SENSE_IN input into the first scan sense driver 10 may bethe sense start pulse SESP. In addition, the scan input signal SCAN_INinput into a second scan sense driver 11 may be the first scan enablesignal. The sense input signal SENSE_IN input into the second scan sensedriver 11 may be the first sense enable signal SENSE_EN[1]. The signalsinto and out of scan sense drivers 12 and 13 may be provided in asimilar manner.

In an example embodiment, the pixel 610 in the pixel array 600 includesa scan driving unit 611 and a sensing unit 613. The scan driving unit611 provides a voltage corresponding to data voltage VDATA to an organiclight-emitting diode 615. The sensing unit 613 may test a state of theorganic light-emitting diode 615 based on the sense enable signalSENSE_EN. For example, when the sense enable signal SENSE_EN is enabled,the sense enable transistor 617 corresponding to the sense enable signalSENSE_EN may be turned-on. When the sense enable transistor 617corresponding to the sense enable signal SENSE_EN is turned-on, thesensing voltage VS transferred from the data voltage line VDATA_L may betransferred to the organic light-emitting diode 615 through the senseenable transistor 617. When the sensing voltage VS is transferred to theorganic light-emitting diode 615 through the sense enable transistor617, the corresponding sensing current IS may be transferred to the datavoltage line VDATA_L through the sense enable transistor 617.Malfunction of the organic light-emitting diode 615 may be tested usingthe sensing current IS.

FIG. 15 illustrates another example of control signals for a displaydevice, which, for example, may be display device 20 in FIG. 13, duringa scan time interval SCTI.

Referring to FIGS. 2, 13, and 15, the scan line driver 100 may includethe scan transistors 111 to 119. The scan line driver 100 provides thescan line enable signal SCAN_EN based on the clock signals CLK1 to CLK3,the global clock signal GCLK, and the scan input signal SCAN_IN duringthe scan time interval SCTI. The clock signals CLK1 to CLK3, the globalclock signal GCLK, and the scan input signal SCAN_IN may be providedfrom the controller 200 to the first scan sense driver 10.

The clock signals CLK1 to CLK3 may be selected among a plurality ofS-clock signals, e.g., first to fourth S-clock signals SCLK1 to SCLK4.For example, the first clock signal CLK1 may be the fourth S-clocksignal SCLK4. The second clock signal CLK2 may be the first S-clocksignal SCLK1. The third clock signal CLK3 may be the second S-clocksignal SCLK2. In this case, the scan input signal SCAN_IN may be a scanstart pulse SSP.

For example, when the first clock signal CLK1 is a logic low level, thefirst scan transistor 113 connected to the third node N3 may beturned-on. When the first scan transistor 113 is turned-on, the fourthnode N4 may be at a logic low level. When the fourth node N4 is at alogic low level, the second scan transistor 115 may be turned-on. Whenthe second scan transistor 115 is turned-on, the scan line enable signalSCAN_EN may be at a logic high level.

Subsequently, the scan input signal SCAN_IN that is the scan start pulseSSP may be at a logic low level and the second clock signal CLK2 may beat a logic low level. When the second clock signal CLK2 is at a logiclow level, the third scan transistor 119 may be turned-on. When thethird scan transistor 119 is turned-on, the scan input signal SCAN_INthat is at a logic low level may be transferred to the first node N1.When the first node N1 is at a logic low level, the fourth scantransistor 116 may be turned-on. When the fourth scan transistor 116 isturned-on, the scan line enable signal SCAN_EN may be the third clocksignal CLK3.

In this case, the first scan line enable signal SCAN_EN[1] may be at alogic low level. The scan input signal SCAN_IN input into the secondscan sense driver 11 may be the first scan line enable signalSCAN_EN[1]. In the second scan line driver 100, the second scan lineenable signal SCAN_EN[2] may be generated in the same manner.

FIG. 16 illustrates another example of control signals for a displaydevice, which, for example, may be display device 20 in FIG. 13, duringa sense time interval.

Referring to FIGS. 4, 13, and 16, the sense driver 300 may include thesense transistors 311 to 317 and 319. The sense driver 300 provides thesense enable signal SENSE_(—) EN based on the clock signals CLK1 to CLK3and the sense input signal SENSE_(—) IN during the sense time intervalSETI. The clock signals CLK1 to CLK3 and the sense input signal SENSE_INmay be provided from the controller 200 to the first scan sense driver10.

The clock signals CLK1 to CLK3 may be selected from among a plurality ofS-clock signals, e.g., first to fourth S-clock signals SCLK1 to SCLK4.For example, the first clock signal CLK1 may be the fourth S-clocksignal SCLK4. The second clock signal CLK2 may be the first S-clocksignal SCLK1. The third clock signal CLK3 may be the second S-clocksignal SCLK2. The sense input signal SENSE_IN may be a sense start pulseSESP.

For example, when the first clock signal CLK1 is at a logic low level,the first sense transistor 313 connected to the eighth node N8 may beturned-on. When the first sense transistor 313 is turned-on, the ninthnode N9 may be at a logic low level. When the ninth node N9 is at alogic low level, the second sense transistor 315 may be turned-on. Whenthe second sense transistor 315 is turned-on, the sense enable signalSENSE_EN may be at a logic high level.

Subsequently, the sense input signal SENSE_IN that is the sense startpulse SESP may be at a logic low level and the second clock signal CLK2may be at a logic low level. When the second clock signal CLK2 is at alogic low level, the third sense transistor 319 may be turned-on. Whenthe third sense transistor 319 is turned-on, the sense input signalSENSE_IN that is at a logic low level may be transferred to the sixthnode N6. When the sixth node N6 is at a logic low level, the fourthsense transistor 316 may be turned-on. When the fourth sense transistor316 is turned-on, the sense enable signal SENSE_EN may be the thirdclock signal CLK3.

In this case, the first sense enable signal SENSE_EN[1] may be at alogic low level. The sense input signal SENSE_IN input into the secondscan sense driver 11 may be the first sense enable signal SENSE_EN[1].In the second sense driver 300, the second sense enable signalSENSE_EN[2] may be generated in the same manner.

In an example embodiment, the controller 200 may control waveforms ofthe clock signals CLK1 to CLK3 based on the scan time interval SCTI andthe sense time interval SETI. For example, the controller 200 mayprovide the clock signals CLK1 to CLK3. A time interval when the clocksignals CLK1 to CLK3 provided during the scan time interval SCTImaintain a first logic level may be a first time interval. A timeinterval when the clock signals CLK1 to CLK3 provided during the sensetime interval SETI maintain a first logic level may be a second timeinterval ST. The second time interval ST may be different from the firsttime interval. For example, the first logic level may be the logic lowlevel and the second logic level may be the logic high level. The firsttime interval may be longer (e.g., two times longer) than a horizontaltime 1H. The horizontal time 1H may be a predetermined time interval.The horizontal time 1H may be a time interval when the scan line isenabled.

In an example embodiment, a time interval between adjacent one of theclock signals CLK1 to CLK3 provided during the scan time interval SCTImay be a third time interval. For example, during the scan time intervalSCTI, the time interval between the time when the first S-clock signalSCLK1 transitions from a logic high level to a logic low level and thetime when the second S-clock signal SCLK2 transitions from a logic highlevel to a logic low level may be the third time interval. The thirdtime interval may be the horizontal time 1H that is predetermined.

In an example embodiment, a time interval between adjacent ones of theclock signals CLK1 to CLK3 provided during the sense time interval SETImay be the second time interval ST. For example, during the sense timeinterval SETI, the time interval between the time when the first S-clocksignal SCLK1 transitions from a logic high level to a logic low leveland the time when the second S-clock signal SCLK2 transitions from alogic high level to a logic low level may be the second time intervalST. The second time interval ST may be may be greater than, for example,several microseconds. In an example embodiment, the first time intervalmay be greater than the third time interval. The second time interval STmay be greater than the first time interval. For example, the first timeinterval may be longer (e.g., two times longer) than a horizontal time1H. The third time interval may be equal to the horizontal time 1H. Inthis case, the first time interval may be greater than the third timeinterval.

In an example embodiment, the first time interval may be equal to thethird time interval. The first time interval and the third time intervalmay be a horizontal time 1H. The horizontal time 1H may be apredetermined time interval. The first time interval may be a timeinterval when the clock signals CLK1 to CLK3 provided during the scantime interval SCTI maintain the first logic level. The time intervalwhen the clock signals CLK1 to CLK3 provided during the scan timeinterval SCTI maintain the first logic level may be a time interval whenthe scan line is enabled. The third time interval may be a time intervalbetween adjacent ones of the clock signals CLK1 to CLK3 provided duringthe scan time interval SCTI.

In one embodiment, the scan sense driver 10 may decrease the layout areaby generating the sense enable signal SENSE_EN and applying the clocksignals CLK1 to CLK3 to the sense driver 300.

FIG. 17 illustrates an embodiment of a mobile device 700 which includesa processor 710, a memory device 720, a storage device 730, aninput/output (I/O) device 740, a power supply 750, and anelectroluminescent display device 760. The mobile device 700 may furtherinclude a plurality of ports for communicating a video card, a soundcard, a memory card, a universal serial bus (USB) device, or otherelectronic systems.

The processor 710 may perform various computing functions or tasks. Theprocessor 710 may be for example, a microprocessor, a central processingunit (CPU), etc. The processor 710 may be connected to other componentsvia an address bus, a control bus, a data bus, etc. Further, theprocessor 710 may be coupled to an extended bus such as a peripheralcomponent interconnection (PCI) bus.

The memory device 720 may store data for operations of the mobile device700. For example, the memory device 720 may include at least onenon-volatile memory device such as an erasable programmable read-onlymemory (EPROM) device, an electrically erasable programmable read-onlymemory (EEPROM) device, a flash memory device, a phase change randomaccess memory (PRAM) device, a resistance random access memory (RRAM)device, a nano-floating gate memory (NFGM) device, a polymer randomaccess memory (PoRAM) device, a magnetic random access memory (MRAM)device, a ferroelectric random access memory (FRAM) device, and/or atleast one volatile memory device such as a dynamic random access memory(DRAM) device, a static random access memory (SRAM) device, a mobiledynamic random access memory (mobile DRAM) device, etc.

The storage device 730 may be, for example, a solid state drive (SSD)device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I/Odevice 740 may be, for example, an input device such as a keyboard, akeypad, a mouse, a touch screen, and/or an output device such as aprinter, a speaker, etc. The power supply 750 may supply power foroperating the mobile device 700. The electroluminescent display device760 may communicate with other components via the buses or othercommunication links.

The present embodiments may be applied to any mobile device or anycomputing device. For example, the present embodiments may be applied toa cellular phone, a smart phone, a tablet computer, a personal digitalassistant (PDA), a portable multimedia player (PMP), a digital camera, amusic player, a portable game console, a navigation system, a videophone, a personal computer (PC), a server computer, a workstation, atablet computer, a laptop computer, etc.

By way of summation and review, as the radiation time of an organiclight-emitting diode increases, luminous efficiency may decrease. Whenthe luminous efficiency of an organic light-emitting diode decreases,the image generated by a display device which includes the organiclight-emitting diode may degrade.

In accordance with one or more of the aforementioned embodiments, a scansense driver generates signals for testing a state (e.g., malfunction orother abnormal or aberrant condition) of an organic light-emittingdiode, for example, in order to determine degradation taking place in adisplay device. In accordance with these or other embodiments, the scansense driver decreases a layout area by generating a sense enable signalwith one or more clock signals.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of skill in the art as of thefiling of the present application, features, characteristics, and/orelements described in connection with a particular embodiment may beused singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwiseindicated. Accordingly, it will be understood by those of skill in theart that various changes in form and details may be made withoutdeparting from the spirit and scope of the present invention as setforth in the following claims.

What is claimed is:
 1. A scan sense driver, comprising: a scan linedriver to provide a scan line enable signal based on a plurality ofclock signals, a global clock signal, and a scan input signal during ascan time interval; and a sense driver to provide a sense enable signalbased on the clock signals and a sense input signal during a sense timeinterval, wherein the sense driver is to provide the sense enable signalduring a period when an organic light-emitting diode is to be tested. 2.The scan sense driver as claimed in claim 1, wherein waveforms of theclock signals provided during the scan time interval are different fromthe waveforms of the clock signals provided during the sense timeinterval.
 3. The scan sense driver as claimed in claim 2, wherein: atime interval when the clock signals provided during the scan timeinterval have a first logic level is a first time interval, a timeinterval when clock signals provided during the sense time interval havethe first logic level is a second time interval, and the second timeinterval is different from the first time interval.
 4. The scan sensedriver as claimed in claim 3, wherein the sense input signal has asecond logic level during the scan time interval.
 5. The scan sensedriver as claimed in claim 3, wherein the scan input signal has a secondlogic level during the sense time interval.
 6. The scan sense driver asclaimed in claim 3, wherein: a time interval between adjacent ones ofthe clock signals provided during the scan time interval is a third timeinterval, and a time interval between adjacent ones of the clock signalsprovided during the sense time interval is the second time interval. 7.The scan sense driver as claimed in claim 6, wherein the first timeinterval is greater than the third time interval.
 8. The scan sensedriver as claimed in claim 7, wherein: the first time interval is longerthan a horizontal time having a predetermined time interval, and thethird time interval is substantially equal to the horizontal time. 9.The scan sense driver as claimed in claim 6, wherein the second timeinterval is greater than the first time interval.
 10. The scan sensedriver as claimed in claim 6, wherein the first time interval issubstantially equal to the third time interval.
 11. The scan sensedriver as claimed in claim 10, wherein: the first time interval and thethird time interval correspond to a horizontal time, and the horizontaltime has a predetermined time interval.
 12. The scan sense driver asclaimed in claim 1, wherein: the sense driver is to provide the senseenable signal based on a total operation time, and the total operationtime includes a time when the scan sense driver is to operate.
 13. Thescan sense driver as claimed in claim 1, wherein, the sense driver is toprovide the sense enable signal when scan sense driver is turned-on. 14.A display device, comprising: a controller to provide a plurality ofclock signals, a global clock signal, a scan start pulse, and a sensestart pulse; a plurality of scan sense drivers to provide scan lineenable signals and sense enable signals based on the clock signals, theglobal clock signal, the scan start pulse, and the sense start pulse;and a pixel array to operate based on the scan line enable signals andthe sense enable signals, wherein each of the scan sense driversincludes: a scan line driver to provide the scan line enable signalbased on the clock signals, the global clock signal, and a scan inputsignal during a scan time interval; and a sense driver to provide thesense enable signal based on the clock signals and a sense input signalduring a sense time interval, wherein the sense driver is to provide thesense enable signal during a period when an organic light-emitting diodeof a pixel in the pixel array is to be tested.
 15. The display device asclaimed in claim 14, wherein: the scan input signal input into a firstscan sense driver of the plurality of scan sense drivers is the scanstart pulse, and the sense input signal input into the first scan sensedriver of the plurality of scan sense drivers is the sense start pulse.16. The display device as claimed in claim 14, wherein the pixelincludes: a scan driver to provide a voltage corresponding to datavoltage to a organic light-emitting diode; and a sensor to test for amalfunction of the organic light-emitting diode based on the senseenable signal.
 17. The display device as claimed in claim 14, whereinthe controller is to control waveforms of the clock signals based on thescan time interval and the sense time interval.
 18. The display deviceas claimed in claim 17, wherein the controller provides the clocksignals, a time interval when the clock signals provided during the scantime interval have a first logic level is a first time interval, a timeinterval when the clock signals provided during the sense time intervalhave the first logic level is a second time interval, and the secondtime interval is different from the first time interval.
 19. The displaydevice as claimed in claim 18, wherein: a time interval between adjacentones of the clock signals provided during the scan time interval is athird time interval, a time interval between adjacent ones of the clocksignals provided during the sense time interval is the second timeinterval, the first time interval is greater than the third timeinterval, and the second time interval is greater than the first timeinterval.
 20. The display device as claimed in claim 19, wherein: thefirst time interval is equal to the third time interval, the first timeinterval and the third time interval correspond to a horizontal time,and the horizontal time is a predetermined time interval.